Situational awareness: A newly-built pedestrian bridge at Florida International University in Miami collapsed today. The current number of fatalities and injured has not been released by authorities. More.

1 big thing: Russia probe reached Trump Org

Robert Mueller has subpoenaed the Trump Organization for documents including those related to Russia, the N.Y. Times' Michael Schmidt and Maggie Haberman report.

Why it matters: "The order is the first known instance of the special counsel demanding records directly related to President Trump’s businesses..."

Details:

"The breadth of the subpoena was not clear, nor was it clear why Mr. Mueller issued it instead of simply asking for the documents..."

"The Trump Organization has typically complied with requests from congressional investigators for documents for their own inquiries into Russian election interference, and there was no indication the company planned to fight Mr. Mueller’s order."

"The Trump Organization has said that it never had real estate holdings in Russia, but witnesses recently interviewed by Mr. Mueller have been asked about a possible real estate deal in Moscow."

2. What you missed

Paul Ryan holds up a pint of Guinness as he proposes a toast during the Friends of Ireland luncheon today. Photo: Alex Edelman-Pool/Getty Images

James Comey book tour: I'll be moderating a conversation with the former FBI Director on April 30 in D.C. as part of the nationwide tour for his book, out April 17th. Details.

Scoop: Benjamin Netanyahu thinks Trump will most likely withdraw the U.S. from the Iran nuclear deal in May. What it means.

The leaders of the U.S., U.K., Germany and France issued a rare joint statement unequivocally blaming Russia for the poisoning of Sergei Skripal. Read it. ... The U.S. also added new sanctions over meddling.

The F.D.A. is moving ahead with new rules that would reduce nicotine in cigarettes to non-addictive levels. More.

North Dakota Sen. Heidi Heitkamp joins a growing list of vulnerable Democrats up for re-election this year who don't want to be viewed as Clinton Democrats.The list.

3. 1 nerdy thing

Unpredictable climate and natural disasters like earthquakes may have spurred early humans to create innovative tools and ways to communicate earlier than previously thought, according to 3 studies published Thursday in Science.

Quote"It's not just humans changing but really the entire ecosystem. It's a picture that's bigger than just the human ancestors themselves."